12123818656909 has 2 divisors, whose sum is σ = 12123818656910. Its totient is φ = 12123818656908.

The previous prime is 12123818656891. The next prime is 12123818656979. The reversal of 12123818656909 is 90965681832121.

12123818656909 is digitally balanced in base 2, because in such base it contains all the possibile digits an equal number of times.

It is a weak prime.

It can be written as a sum of positive squares in only one way, i.e., 6453809989225 + 5670008667684 = 2540435^2 + 2381178^2 .

It is a cyclic number.

It is not a de Polignac number, because 12123818656909 - 2²⁹ = 12123281785997 is a prime.

It is a super-2 number, since 2×12123818656909² (a number of 27 digits) contains 22 as substring.

It is a congruent number.

It is not a weakly prime, because it can be changed into another prime (12123818656979) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 6061909328454 + 6061909328455.

It is an arithmetic number, because the mean of its divisors is an integer number (6061909328455).

Almost surely, 2^{12123818656909} is an apocalyptic number.

It is an amenable number.

12123818656909 is a deficient number, since it is larger than the sum of its proper divisors (1).

12123818656909 is an equidigital number, since it uses as much as digits as its factorization.

12123818656909 is an evil number, because the sum of its binary digits is even.

The product of its (nonzero) digits is 11197440, while the sum is 61.

The spelling of 12123818656909 in words is "twelve trillion, one hundred twenty-three billion, eight hundred eighteen million, six hundred fifty-six thousand, nine hundred nine".